Pumpimg system.



E. L. DUNN.

PUMPING SYSTEM.

APPLICATION FILED SEPT. s, 1909.

1,037,879, Patented Sept. 10,1912

quently, there is an excessive strain and "wear and tear on the apparatus, requiring I According to this invention, I propose to provide a pumping system UNITED s'rarns EDWARD L. DUNN, 0F WORCESTER, MA

PATENT OFFICE.

SSACHUSETTS, ASSIGNOR TO STANDARD PLUNGER ELEVATOR COMPANY, OF NEWV YORK, N. Y., A CORPORATION OF NEW JERSEY.

PUMPING 1 37,879. Specification of To all whom it may concern:

. Be it known that I, EDW'ARD L. DUNN, acitizen of the United States, residing at lVorcester, in the county of \Vorcester and State of Massachusetts, have invented certain new and useful Improvements in Pumping Systems, of which the following 'is a full, clear, and exact specification.

This invention relates to automatic pumping systems, and more particularly has reference to pressure pumping systems wherein it is desired to automatically maintain a supply of hydraulic fluid in a tank under an approximately constant pressure as for use in operating elevators, presses and other machinery. In such systems as now commonly employed an electrically driven pump is used for pumping the water into the storage tank,'and this pump and its motor arc automatically started and stopped as the pressure in the tank falls or rises. In such a system it will be seen that: the motor must be started and stopped a great number of times where the machinery operated by the system is in frequent use, sometimes as frequently as once every minute. lVhere there is a large pump it is a difiicult matter to automatically start and stop it so frequently, and furthermore the starting load on a pump is very great by reason of the inertia of the column of water which has to be moved, thereby requiring excessive starting current for the motor. Consefrequent attention and considerable re ,newal.

wherein a preetermined pressure will be automatically maintained in the pressure tank by a continuously running motor and pump, combined with automatic valve controlling mechanism whereby as long as there is a predetermined pressure in the tank the pump simply circulates the water through the discharge tank, but when the pressure in the storage tank falls, the valve mechanism automatically operates to connect the Application filed September 3, 1909.

SYSTEM.

Lett rs Pa n Patented Sept. 10, 1912.

Serial No. 516,100.

restore the pressure, whereupon the automatic valve is again shifted to connect the discharge side of the pump to the discharge tank. Thereby there is an ultimate saving in current and also excessive strain an wear and tear on the machinery avoided.

I n the specific embodiment of the invention herein shown, the discharge of the pump is controlled by a pressure operated direction valve, and the pressure to this direction valve is automatically governed by a solenoid operated pilot valve and a pressure actuated switch system controlled by the storage tank pressure which controls the pilot valve solenoid.

The invention will be more fully understood in connection with the description of the accompanying drawing, wherein 1 represents a pump, and a motor belted thereto through pulley 3. 4t a pressure tank hav ing an inlet pipe 5, 6 the discharge tank into which the exhaust from the machinery will be discharged through a pipe 7, and 8 is the supply pipe from the pressure tank 4 to the machinery. The machinery and the controlling valves are not herein shown,,'not being necessary to a full understanding of this invention. 9 is the pump intake pipe leading from the lower portion of tank 6 to the pump 1, and 10 is the pump discharge leading to the direction valve 11. The direction valve comprises a stem 12 having at each end operating pistons 13, 1a and a controlling piston 15. Also connected to the direction valve 11 is a discharge pipe 16 discharging into the tank 6. In the position shown, it will be seen that the pump is taking water from the tank (3 through the pipe 9 and discharging it through the pipes 1.0 and 16 into the discharge side of the pump to the tank to connected to the direction valve 11 above 1,037,879 f I v 3 the low pressure s11 ply or to close such dis-v the other direction, and a i'essm'e operated charge, and means or controlling said direcswitch for controlling sai solenoid. 7 10 tionvalve comprising a pilot valve having '1 In'testimon whereof I afiix my signature, passages for motor fluid connected to the rein presence 0 two witnesses.-

5 spective sides of said direction valve for I EDWARD L. DUNN,

moving it in opposite direotions, means for Witnesses: f moving said pllot valve in one direction by O. Fo mms'r WESSON, tank pressure, a solenoid for moving it in CATHARI'VNE. I, HARTNETT. 

